Golf club assembly method and golf club

Abstract

To provide a golf club in which the balance of action between the directionality of the spine arrangement for increasing the rigidity of the shaft and the position of the eccentric center of gravity in the head is secured in an optimal state. [Solution] In a golf club (G) having a head (12) at the tip of a shaft (10) and a grip (13) at the butt end, a spine (S) is arranged to extend along the axial direction of the shaft (10) to create a highly rigid overlapping portion on the circumferential surface of the shaft (10). The head (12) and the shaft (10) are assembled and integrated so that the directionality (OO) maintains a substantially parallel relationship capable of countering the directionality (P) of the impact applied to the face surface (F) of the head (12).

Description

[Technical Field]

[0001] The present invention relates to a golf club Assembly method and golf club Regarding. [Background technology]

[0002] As is well known, golf clubs differ from baseball bats in that the head of either a wood club or an iron club is bent in an almost L-shape from the tip of the shaft, and the center of gravity of the head is in an eccentric position offset from the axis of the shaft, resulting in an eccentric center of gravity.

[0003] Furthermore, whether it's a carbon shaft or a steel shaft, a spine (a part of the shaft that overlaps or is unevenly thickened) forms on the shaft's circumferential surface during manufacturing, and the shaft's rigidity (stiffness) is not uniform along the circumference. The shaft's rigidity is higher in the direction in which the spine is located and lower in other directions. As a result, when hitting the ball, the shaft is prone to bending / twisting in the specific direction of low rigidity, causing the head to swing around easily.

[0004] In other words, the performance of a golf club is particularly dependent on the spine of the shaft and the center of gravity of the head, and if the spine's orientation and the head's center of gravity are not properly balanced when assembled, in other words, if the shaft is not rigid enough to withstand the swing of the head, the shaft will not be able to withstand the impact of the head when hitting the ball and will give way, causing the head to swing around the shaft, making the ball's flight direction unstable and reducing the distance it travels. This will also cause twisting forces on the player's wrist, which can injure their joints and muscles.

[0005] Therefore, while the assembly of the shaft and head is the most important aspect, even if there is a problem with the assembly, the spine of the shaft cannot be seen from the outside, and the correct adjustment (standard) that applies to all golf clubs is unknown, so the specific adjustment method is unknown.As a result, even for expensive golf clubs that are equipped with adjustment devices with various characteristics, not everyone is able to make effective use of these adjustment devices.

[0006] In this regard, the conventional approach described in Non-Patent Document 1 assembles the head with the spine of the shaft pointing in the 6 o'clock direction to reduce the "toe down" phenomenon, in which the tip of the head droops during the downswing of the golf club. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] "What is the 'spine' of a shaft?" Retrieved April 10, 2025, Internet<URL:https: / / golfmechanic.co.jp> Summary of the Invention [Problem to be solved by the invention]

[0008] As shown in the cross-sectional plan view of Figure 11, the assembly state of the shaft and head described in Non-Patent Document 1 is such that the 6 o'clock orientation (OO) of the spine (S) of the shaft (10) where rigidity is high intersects at a substantially right angle (θ) with the direction of impact (P) applied to the face surface (F) of the head (12) that hits the ball. The orientation directly facing the direction of impact (P) and able to resist the impact is the orientation of the shaft (10) where rigidity is low. Therefore, when hitting the ball, the shaft (10) twists / bends, and cannot withstand the swing of the head (12), and it is difficult to expect any effect in reducing the toe-down phenomenon. [Means for solving the problem]

[0009] In view of these problems, the inventor of the present invention discovered that it is possible to make optimal adjustments for each club by keeping the shaft and head face horizontal and always applying a stable, constant force in the same vertical direction from above or below, as would occur when a player actually hits a ball with a golf club, and experimentally vibrating the golf club in its natural assembled state, and learning its performance from its natural behavior, thereby achieving optimal adjustments for each club, which led to the creation of the present invention.

[0010] That is, the present invention aims to fundamentally solve the above problems, and in order to achieve this aim, claim 1 This method of assembling a golf club shaft and head includes a preparation step of attaching and fixing a grip to the butt end of the shaft, and fixing the head to the tip of the shaft with adhesive in a temporary assembly state that is easy to remove but will not move even if strong force is applied.

[0011] A verification process in which the shaft of the prepared golf club is kept horizontal, the face of the head is positioned so that it faces upward, the grip is attached and fixed to a support device so that it does not rotate, and a constant force is applied vertically to the face of the head to check the natural swing behavior of the golf club;

[0012] If the verification process finds that the head of the golf club is unstable, swinging irregularly in directions other than the vertical direction or swinging irregularly clockwise or counterclockwise, the golf club is temporarily removed from the support device, and an assembly adjustment process is carried out in which either the head or the shaft removed from the head is kept fixed, while the other is rotated clockwise or counterclockwise little by little, and the other rotating side and one fixed side are temporarily fixed together with an adhesive.

[0013] In the assembly adjustment process, the same verification as in the verification process is repeated each time the head is rotated, and when the head of the golf club finally achieves a stable behavior of swinging linearly only in the vertical direction, the shaft is removed from the head, and the head and shaft are assembled and integrated with an adhesive in an adjusted state in which they are aligned with each other in a finishing process.

[0014] In the above-mentioned assembly adjustment process, when the rotating side of the head and the shaft extracted from it is first rotated relative to the fixed side, a mark is provided on the other side to indicate how much it has been rotated.

[0015] When the golf club head finally achieves the stable behavior by repeating the assembly adjustment process and the subsequent verification process, a mark serving as a reference for alignment that corresponds to the mark for determining the degree of rotation that was given to the other rotating side is given to one of the fixed sides, and the head and shaft are assembled and integrated with an adhesive in an adjusted state in which they are aligned based on both marks.

[0016] In claim 2, in the assembly adjustment process, the mark for determining the degree of rotation, which is given to the other of the rotating side of the head and the shaft extracted from it, is a straight line of a certain length, and the mark for alignment, which is given to one of the fixed sides, is a straight line of a certain length that corresponds to the mark for determining the degree of rotation,

[0017] Each of these is characterized by being marked on the surface of masking tape wrapped around the hosel and shaft of the head so that they form a continuous straight line when aligned.

[0018] Claim 3 is characterized in that, at the end of the finishing process, the fixed state of the grip to the shaft of the golf club is confirmed, and the grip is attached and fixed to a support device in the verification process so that it does not rotate, and by performing the verification process, it is also included a process of confirming whether the head of the golf club behaves as if it swings linearly only along the vertical direction.

[0019] Claim 4 provides a golf club, characterized in that the shaft and head are assembled by the assembly method described in claim 1 or 2. [Effects of the Invention]

[0020] According to the above configuration of claim 1, the shaft of the golf club is kept horizontal, the face of the head is positioned facing upward, and the two points of the grip that are grasped with both hands are attached and fixed to the support device so that they do not rotate. A constant vertical force is then applied to the face of the head to check the natural swinging behavior of the golf club, and the assembly adjustment work of rotating the shaft and head relatively clockwise or counterclockwise little by little is repeated until the head achieves a stable behavior of swinging linearly only along the vertical direction. Therefore, the assembly condition, which is normally invisible to the naked eye, can be inspected and diagnosed by visually observing the behavior, and the assembly condition can be adjusted to the best (optimum), which is very significant in terms of visualization.

[0021] In this case, in the above configuration of claim 1, in the preparation process, the head is attached and fixed to the tip of the shaft in a temporary assembled state so that it is easy to remove, but so that it will not move (will not spin freely) even if a strong force is applied, which has the effect of making it possible to perform the subsequent insertion and removal of the shaft and head, which is necessary when repeating the assembly adjustment process and verification process, quickly, easily, and efficiently.

[0022] Furthermore, in the above-mentioned behavior verification, a constant vertical force is applied from above or below to the face of the golf club when the head is in an upward position, and because this constant vertical force is applied as the most stable natural force, it can serve as a common inspection standard for all golf clubs, regardless of the size, shape, or position of the center of gravity of the head, or the length, weight, strength, etc. of the shaft. As a result, it is useful for obtaining the optimal (best) assembly state of the shaft and head for each individual golf club.

[0023] In this regard, if the grip of a golf club is fixed to a support device so that it does not rotate, and the shaft is kept horizontal, but the face of the head that bends downward from the tip of the shaft is held vertical, and a constant horizontal force is applied to the face and swung, various forces such as gravity, centrifugal force, the force of the lever due to the cantilevered state at the grip, the weight of the head, and other various forces are applied in various directions to the golf club, and regular, stable behavior cannot be obtained. As a result, this cannot be used as an inspection method to serve as a standard for assembling and adjusting the shaft and head.

[0024] As in the configuration described in claim 1, if the inspection method involves swinging the head vertically by holding the face of the head facing upward and applying a constant force equivalent to the force of the ball to the face, even though gravity, centrifugal force, the force of the lever, and other various forces will produce amplitudes of varying magnitude depending on the weight of the head, all of these forces will be applied uniformly (uniformly) in the vertical direction, so that a stable behavior of regular swinging only along the vertical direction (linear reciprocating motion in the up and down direction) will naturally be obtained, and as a result, this inspection method can be adopted as a suitable standard for assembling and adjusting the shaft and head of any golf club.

[0025] Furthermore, in the above configuration of claim 1, by repeating the assembly adjustment process and the subsequent verification process, when the golf club head finally achieves a stable behavior of swinging linearly only along the vertical direction, the head and shaft are assembled and integrated with adhesive in an adjusted state in which both the mark for determining the degree of rotation attached to the other rotating side and the mark serving as a reference for alignment attached to one of the fixed sides are aligned, so that the assembly state can be fine-tuned with high precision, and if the configuration of claim 2 is adopted in particular, the performance of the assembled golf club will be further improved by this high-precision fine adjustment.

[0026] Furthermore, if the above configuration of claim 3 is adopted, in the golf club assembly adjustment process, each time the shaft and head are rotated relatively a little at a time, the head of the golf club is repeatedly checked and verified to see if it has achieved stable behavior of swinging linearly only along the vertical direction, and the achievement of this behavior is finally confirmed, which has the effect of providing a golf club with a highly reliable assembly state through this confirmation.

[0027] According to the configuration of claim 4, the golf club has an optimal (best) balance between the position of the center of gravity in the head and the directionality of the spine arrangement in the shaft, and anyone who plays with this golf club can achieve improved swing stability, ball distance and ball directionality, and other benefits. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is an enlarged cross-sectional plan view perpendicular to the axis of a carbon shaft of a golf club. [Figure 2] 1 is a schematic perspective view showing an entire ready-made golf club. [Figure 3] FIG. 3 is a perspective view showing the exploded state of FIG. 2. [Figure 4] 10 is a perspective view of a state in which the golf club is attached and set to the support device in the assembly and adjustment process of the present invention. FIG. [Figure 5] FIG. 5 is an enlarged front view of FIG. [Figure 6] FIG. 1 is a front view of a golf club head swinging in an irregular elliptical path. [Figure 7] FIG. 10 is a plan view showing a state in which a mark for determining the degree of rotation is provided on a shaft. [Figure 8] FIG. 1 is a front view showing stable behavior in which the head of a golf club swings regularly only along the vertical direction. [Figure 9] FIG. 10 is a plan view showing an adjusted state in which the mark on the shaft side and the mark on the head side are aligned in a straight line. [Figure 10] 1 is a cross-sectional plan view schematically showing a golf club in a state in which a shaft and a head according to the present invention have been assembled and adjusted; [Figure 11] 11 is a cross-sectional plan view corresponding to FIG. 10, schematically showing a conventional golf club in which the spine of the shaft is oriented at 6 o'clock. DETAILED DESCRIPTION OF THE INVENTION

[0029] Before describing preferred embodiments of the present invention in detail with reference to the drawings, a brief explanation of the spine of a shaft will be provided. When the shaft 10 of a golf club G is a so-called carbon shaft, as shown in the enlarged cross-sectional plan view of FIG. 1 perpendicular to the axis of the shaft 10, several plies of carbon fiber sheet-like prepreg 11 are wound around a mandrel (not shown) during manufacturing so that a predetermined width (W) of overlap occurs between the winding start edge 11a and the winding end edge 11b. This overlapping portion of a predetermined thickness (T) forms a spine (S) that extends axially of the shaft 10 like a backbone.

[0030] Therefore, the rigidity (stiffness) of the shaft (10) is high (strong) on ​​the meridian (OO) of the shaft (10) passing through the spine (S), but is low (weak) in arrangement directions where there is no spine (S) that intersects with this arrangement direction (OO), and this low rigidity arrangement direction is prone to causing bending / torsional deformation and vibration.

[0031] This is true not only for carbon shafts, but also for so-called steel shafts, which are made by bending a flat steel plate and then lap welding a specified width, as the lap welded part extends as a spine, which is the same as the carbon shaft mentioned above.

[0032] In either case, the orientation of the spine (S) cannot be seen from the outside of the completed shaft (10), and the position of the center of gravity of the head (12) offset from the axis of the shaft (10) cannot be accurately determined.

[0033] Therefore, in the embodiment of the present invention, the shaft 10 and head 12 of the golf club G are assembled through the steps shown in Figures 2 to 9, but the assembly adjustment step described below is particularly a precise fine adjustment performed by hand in a workshop. The assembly method will be explained in the order of the steps as follows.

[0034] That is, when starting work with a ready-made golf club (G) having a head (12) at the thin tip of a shaft (10) and a grip (13) at the thick handle, the golf club (G) is first disassembled as shown in Figures 2 and 3 as a preparation process for repeatedly carrying out the verification process and assembly adjustment process described below.

[0035] Specifically, the grip (13) is removed from the shaft (10), and the double-sided tape (not shown), product labels (stickers), and other unnecessary objects, impurities, and obstacles attached to the shaft (10) are removed and cleaned thoroughly. The socket (14) and head (12) are also removed from the shaft (10).

[0036] Then, the adhesive adhering to the inside of the hosel 15 of the head 12 and to the shaft 10 is removed, and the grip 13 is attached and fixed to the butt end of the shaft 10 without the double-sided tape or product label, and the head 12 is attached and fixed to the tip end of the shaft 10 with an adhesive (preferably an epoxy resin adhesive) so that it can be easily removed, but still remains in a temporary assembled state that does not move (does not spin freely) even when a strong force is applied. This is to enable the shaft 10 and head 12 to be inserted and removed quickly and efficiently when repeating the assembly adjustment and verification processes.

[0037] Next, the shaft (10) of the golf club (G) prepared in the above-mentioned temporarily fixed state is held horizontally as shown in Figures 4 and 5, with the face (F) of the head (12) facing upward, and the two points of the grip (13) that are grasped as if with both hands are fixed to the support device (M) by the clamps (16) so that it does not rotate (turn). Then, a weak (light) constant vertical force (starting force) is applied from above or below to the face (F) of the head (12) using the fingertips of the working hand, and the swinging behavior of the golf club (G), particularly the head (12), is investigated and verified.

[0038] In this case, the test method of applying a constant vertical force with the face surface (F) of the head (12) facing upward is intended to reproduce and examine the state at the time of hitting the ball. The reason for adopting this method is that it allows the application of the most natural and stable force that is not influenced by the length and weight of the shaft (10) or the shape and weight of the head (12), and by swinging the club vertically using this natural and stable force as a standard, it is useful for accurately determining (diagnosing) the assembly state and performance of the golf club (G).

[0039] If, during the verification process, the head (12) of the golf club (G) swings around in an irregular elliptical trajectory in a clockwise or counterclockwise direction, or swings irregularly in a horizontal or diagonal direction, or swings randomly in a direction other than the vertical direction, as shown in Figure 6, a front view seen from the tip side, or if the head (12) behaves unstable, the golf club (G) is removed from the support device (M) of Figures 4 and 5, and the shaft (10) removed from the head (12) is rotated clockwise or counterclockwise little by little, and the head (12) is temporarily fixed to the rotated shaft (10) with an adhesive, thereby performing an assembly adjustment.

[0040] At the start of the assembly adjustment work, in which the shaft (10) extracted from the head (12) is first rotated little by little in the clockwise or counterclockwise direction, a mark (17) is provided on the rotating shaft (10) so that it can be determined how much the shaft (10) has been rotated relative to the fixed head (12).

[0041] Although an arrow or other mark may be displayed as the mark (17) for indicating the angle of rotation per rotation, it is preferable to wrap masking tape (18) around the surface of the shaft (10) as shown in Figure 7 and draw a colored straight line of a certain length on the masking tape (18) as the mark (17). This way, the mark (17) will not disappear and can be clearly seen any number of times.

[0042] After this assembly and adjustment process, the golf club G is subjected to the same verification process as described above to determine whether the adjustment is satisfactory. The two processes are repeated. Each time the club is rotated slightly clockwise or counterclockwise, the shaft 10 and head 12 are temporarily fixed, and the swing behavior is checked and verified.

[0043] By repeating the assembly adjustment process and the subsequent verification process, if the head (12) of the golf club (G) eventually begins to swing linearly only along the substantially vertical direction as shown by the arrow in Figure 8, it is deemed to be in the optimal (best) adjustment state, and an alignment mark (19) that corresponds to the mark (17) that was provided on the rotating shaft (10) is provided on the hosel (15) of the head (12), which was the fixed side in the assembly adjustment process.

[0044] In this case, "swinging linearly substantially only in the vertical direction" means that the shaft (10) can swing horizontally up to 10 mm to the left and right, and as long as it is within this range, there will be no significant difference in the effects such as the flight distance and directionality of the ball when the same player hits the ball using the same golf club (G).

[0045] The fixed side mark (19) may be displayed as an arrow or other mark, as long as it serves as a reference for alignment when assembling the head (12) and shaft (10). However, when providing the mark (19), it is preferable to shine a light or laser on the joint between the shaft (10) and head (12) that are in the optimal (best) adjusted state.

[0046] In this way, since both are tubular metal bodies, and only the illuminated portion of the circumferential surface glows as if forming a ridge line, it is sufficient to place a ruler on the glowing line and draw a straight line mark (19) on the hosel (15) of the head (12) along the ruler so that the straight line matches the straight line of the mark (17) previously provided on the shaft (10). In this case, it is also desirable to wrap masking tape (20) around the hosel (15) of the head (12) as shown in Figure 9 and draw a colored straight line that will serve as the alignment mark (19).

[0047] After providing the hosel 15 of the head 12 with a mark 19 for alignment when assembling it with the shaft 10, the shaft 10 is temporarily removed from the hosel 15 of the head 12, and any unwanted matter, impurities, or obstacles adhering to the inside of the hosel 15 of the head 12 and the shaft 10 are removed and thoroughly cleaned.

[0048] The shaft 10 and head 12 are then aligned with high precision based on the marks 17 and 19 on the former and the latter, respectively, and then assembled together using an epoxy resin adhesive or other suitable adhesive. Double-sided tape (not shown) is applied to the butt end of the shaft 10, and the grip 13 is attached and fixed to the shaft 10, completing the golf club G. The masking tapes 18 and 20 wrapped around the hosel 15 of the shaft 10 and head 12 can be peeled off after the assembly.

[0049] In the illustrated embodiment, in the assembly adjustment process, the shaft 10 is rotated relative to the fixed head 12. However, this assembly adjustment is performed to ensure the optimal balance between the orientation (OO) of the spine S, which increases the rigidity (strength) of the shaft 10, and the position of the center of gravity in the head 12. Therefore, conversely, the shaft 10 may be fixed and the head 12 may be rotated relative to it. In this case, a mark 17 for indicating the degree of each rotation may be provided on the hosel 15 of the head 12, and a mark 19 for aligning it may be provided on the shaft 10.

[0050] It is also possible to wrap the masking tape (18) (20) and mark the surfaces with the marks (17) (19) on both the hosel (15) of the head (12) and the shaft (10) from the start of the assembly and adjustment work.

[0051] More preferably, at the end of the above-mentioned finishing process, the double-sided tape used to secure the grip (13) to the shaft (10) is dried, and after confirming that the grip (13) is securely fixed without loosening, two points of the grip (13) on the finished golf club (G) are attached and set in a fixed state that prevents it from rotating (rotating) by the clamps (16) to the support device (M) of Figures 4 and 5 used in the verification process above, and the same verification as in the verification process is carried out.

[0052] In other words, by carefully verifying the assembled and adjusted state of the shaft (10) and head (12) in the finished golf club (G), it is possible to confirm whether the head (12) of the golf club (G) swings linearly only along the vertical direction, thereby increasing the reliability of the adjustment state.

[0053] Previously, based on Figures 2 to 9, we explained the case where the assembly work process of the shaft (10) and head (12) is started from a pre-made golf club (G), but it is also possible to adopt an assembly method in which the work starts from the shaft (10) and head (12), which are components of the golf club (G).

[0054] In this case, there is no need to disassemble the ready-made golf club, and a preparation process is carried out in which the grip (13) is attached and fixed to the grip portion of the shaft (10), which is one of the components, and the head (12) is attached to the tip of the shaft (10) in a temporary assembled state that is also easy to remove but will not move even if strong force is applied, and is fixed with adhesive.

[0055] The verification process, assembly and adjustment process, and finishing process that follow the preparation process are all the same as those described for the assembly work of the pre-made golf club (G) above, and by going through these processes, the same assembly and adjustment state as the golf club (G) can be achieved.

[0056] After the above-mentioned finishing process is completed, it is preferable to perform the same verification by attaching and fixing the shaft (10) to the support device (M) shown in Figures 4 and 5 used in the previous verification process so that it cannot rotate (its axis), and checking whether the head (12) swings linearly only along the vertical direction.

[0057] In any case, the stable and regular behavior of the head (12) of the golf club (G) swinging linearly only along the vertical direction means that the head (12) and shaft (10) are in the assembled and adjusted state shown in Figure 10.

[0058] In other words, in this assembled and adjusted state, the directionality (OO) of the arrangement of the spine (S), which increases the rigidity (strength) of the shaft (10), and the directionality (P) of the impact force applied to the face surface (F) of the head (12) when hitting the ball are substantially parallel to each other, and the action (force / strength) relationship between the position of the center of gravity of the head (12), which is bent in an almost L-shape from the tip of the shaft (10), and the directionality (OO) of the arrangement of the spine (S), which extends along the axial direction of the shaft (10), is maintained in an optimal (best) balance.

[0059] As a result, the impact force acting on the face (F) of the head (12) when hitting the ball is directly opposed to the orientation (OO) of the spine (S) which exhibits high rigidity of the shaft (10), and can be received and resisted without being overwhelmed. There is no risk of twisting deformation of the shaft (10), toe-down phenomenon, or swinging of the head (12), and the original performance of the shaft (10) and the original performance of the head (12) in the golf club (G) can be properly maximized.

[0060] Furthermore, to put it paradoxically, if there is even the slightest problem with the assembly of the shaft (10) and the head (12), and the balance between the position of the center of gravity in the head (12) and the orientation (OO) of the spine (S) in the shaft (10) is poor (inappropriate), when the swinging behavior of the golf club (G) is examined in the above-mentioned verification process shown in Figures 4 and 5, the behavior will manifest as an unstable phenomenon that traces a random trajectory as shown in Figure 6, but this would never have been discovered without the adoption of the inspection method in the above-mentioned verification process.

[0061] It was only by examining and verifying the behavior of the golf club (G) using the inspection method of the present invention illustrated in FIGS. 4 and 5 that it was possible to ascertain (diagnose) stable behavior in which the shaft (10) and head (12) are regularly oscillating only along the vertical direction (linear reciprocating motion in the up and down direction) as shown in FIG. 8, which is the correct answer (adjustment target) so to speak for the assembled state of the shaft (10) and head (12). Therefore, by using this as a standard and repeatedly carrying out the assembly adjustment process of the shaft (10) and head (12) and the verification process each time an adjustment is made, it was possible to obtain a golf club (G) in which the above-mentioned balance of actions is maintained at the best (optimum).

[0062] By playing with the golf club (G) of the present invention, regardless of the player's physique, skill, age, experience, etc., and regardless of whether the golf club is equipped with various adjustment devices, anyone can achieve effects such as improved swing stability, improved ball distance and direction, improved meet rate, reduced side spin, and relief from joint pain, muscle pain, and lower back pain. These effects are proven by the high evaluations received from many players who have used the golf club (G) of the present invention. [Explanation of symbols]

[0063] (10) Shaft (12) Head (13) Grip (14) Socket (15) Hogel (16) Clamp (17)(19)····Landmark (18)(20)····Masking tape (F) Face (G) Golf club (M) Golf club support device (S) Spine (OO) Spine orientation (P) Direction of impact when hitting the ball

Claims

1. A method for assembling a golf club shaft and head, comprising a preparatory step of attaching and fixing a grip to the butt end of the shaft, and fixing the head to the tip of the shaft with adhesive in a temporary assembly state that is easy to remove but will not move even if strong force is applied; A verification process in which the shaft of the prepared golf club is kept horizontal, the face of the head is positioned so that it faces upward, the grip is attached and fixed to a support device so that it does not rotate, and a constant force is applied vertically to the face of the head to check the natural swing behavior of the golf club; If the verification process finds that the head of the golf club is unstable, swinging irregularly in directions other than the vertical direction or swinging irregularly clockwise or counterclockwise, the golf club is temporarily removed from the support device, and an assembly adjustment process is carried out in which either the head or the shaft removed from the head is kept fixed, while the other is rotated clockwise or counterclockwise little by little, and the other rotating side and one fixed side are temporarily fixed together with an adhesive. In the assembly adjustment process, the same verification as in the verification process is repeated each time the head is rotated, and when the head of the golf club finally achieves a stable behavior of swinging linearly only in the vertical direction, the shaft is removed from the head, and the head and shaft are assembled and integrated with an adhesive in an adjusted state in which they are aligned with each other in a finishing process. In the above-mentioned assembly adjustment process, when the rotating side of the head and the shaft extracted from it is first rotated relative to the fixed side, a mark is provided on the other side to indicate how much it has been rotated. A method for assembling a shaft and a head in a golf club, characterized in that when the golf club head finally achieves the stable behavior by repeating the above assembly adjustment process and the subsequent verification process, a mark serving as a reference for alignment that corresponds to the mark for determining the degree of rotation that was attached to the other rotating side is attached to one of the fixed sides, and the head and shaft are assembled and integrated with an adhesive in an adjusted state aligned based on both marks.

2. In the assembly adjustment process, a mark for determining the degree of rotation to be given to the other of the rotating sides of the head and the shaft extracted from it is a straight line of a certain length, and a mark for alignment to be given to one of the fixed sides is a straight line of a certain length that corresponds to the mark for determining the degree of rotation, 2. The method for assembling a shaft and a head in a golf club according to claim 1, wherein the marks are marked on the surface of masking tape wrapped around the hosel of the head and the shaft, respectively, so that they form a continuous straight line when aligned.

3. A method for assembling a shaft and head in a golf club as described in claim 1, characterized in that it also includes a step of, at the end of the finishing step, checking the fixed state of the grip on the shaft of the golf club, attaching and fixing the grip to a support device in a verification step so that it does not rotate, and performing the verification step to check whether the head of the golf club behaves as if it swings linearly only along the vertical direction.

4. A golf club having a shaft and a head assembled by the assembly method described in claim 1 or 2.

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